Beddr's SleepTuner is an FDA-registered sleep tracker that uses SpO2

Over the past year, every wearable company under the sun has been charging toward providing better sleep tracking - and Fitbit has thus far been leading the charge. Beddr's new SleepTuner is taking things off the wrist and onto your forehead. It's about the size of a postage stamp and as heavy as a nickel,…